


Some Things Better Left Alone

by AngeliaDark



Series: The Papyton Journey of Love [1]
Category: Undertale
Genre: M/M, Post-Pacifist Route, Protective Older Brother Sans, Sans needs to chill out, papyton
Language: English
Status: Completed
Published: 2016-01-11
Updated: 2016-01-11
Packaged: 2018-05-13 07:18:46
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,776
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5699803
Author URL: https://archiveofourown.org/users/AngeliaDark/pseuds/AngeliaDark
Summary: <blockquote class="userstuff">
              <p>Sans overhears something he shouldn't have, and learns that sometimes it's best to not get involved in his brother's love life.</p>
            </blockquote>





	Some Things Better Left Alone

Life really was pretty good on the Surface, once everything was settled in and places were made to accommodate everyone.

The first new settlement was in the valley at the foot of Mt. Ebott, where the open sky and air combined with the shade of the mountain gave everyone both the experience of the Above Ground they wanted combined with the familiarity they were used to, making the transition all the easier.

It seemed like a blur of moments that passed getting everything done. Frisk worked hard as ambassador between the Monsters and the humans—though Asgore and Toriel as advisers and Undyne as a bodyguard certainly helped—and ended up with a fine integration program that bridged the old prejudices and hurts between the two races. Volunteers on both sides met in the middle, exchanging information and forming friendships. Alphys working on the science side and Papyrus on the social side smoothed things along quite nicely.

Homes were built and jobs were made and worked at, the integration efforts pulling everything together as humans and Monsters coexisted. All the hard work and dedication to peace paid off, as schools, jobs, and entertainment became a grand mash of both cultures that everyone seemed to enjoy.

Sans could hardly believe it when six years passed and he suddenly found himself sitting in Grillby's new Surface establishment, taking a breather from his own work and inner thoughts. Much like his time in the Underground, he had a handful of part-time jobs up here as well, ranging from the day janitor at Frisk's school—he switched up the school whenever they changed grades—to cleaning at Grillby's, the bigger customer group requiring more help.

He enjoyed both jobs equally. Keeping an eye on Frisk to make sure they were safe, as well as becoming a favored staff member of the other kids made his work fulfilling. The kids quickly learned that he didn't tolerate bullying, but if you were nice enough to ask, he'd give you a 'shortcut' to make sure you weren't late for class. And despite what some of the teachers complained about his 'laziness', they couldn't find any fault in his work. The school had never been tidier, and any mess that was made was 'suddenly' gone before more complaints could be made.

At the night shift at Grillby's, he just enjoyed to quiet ambiance and friendly atmosphere, doing more people-watching than work most of the time. It almost seemed like a dream, watching humans and Monsters enjoy one another's company, swapping stories and cheering on sports teams on the large TV Grillby had installed, knowing that games could run for awhile, and the longer customers stayed, the more food and drink they would order.

So that's what he was doing today while on break, sitting in a back table and people-watching. He looked up when the door opened and the loud voices of his brother and Mettaton rang through, trying not to let his mood dampen a little.

Mettaton had quickly grown as big a star Above Ground as Under, practically dominating the internet, TV, and even movies and music. Once the novelty of him being a sentient robot faded, everyone saw how far his talent really went and a second wave of obsession washed over the entertainment industry. He was in constant demand for movies and talk shows, and put out new albums every few months, almost always featuring Napstablook's music.

Despite his fame, he never wavered in his loyalty to his friends, always finding time to take off for special holidays and birthdays, and he even found time to settle in a steady relationship.

...if ONLY that relationship hadn't been Sans' brother!

Two years and Sans STILL couldn't believe that his little brother was dating Mettaton. He couldn't believe it when Papyrus announced the news. In fact, he thought it was something of a misunderstanding, or even a joke. Oh, if it was Mettaton's idea of a joke, then Sans was going to show that bucket of bolts HIS idea of A Bad Time.

But it seemed that it WASN'T a joke on Mettaton's part, or even a misunderstanding on Papyrus's. They went on dates, went to some of Mettaton's public events together, and several times, Sans even saw Mettaton BLUSHING over Papyrus's surprisingly romantic gestures. Everyone else thought it was sweet, but Sans just found it disturbing. Maybe he was just biased, but he didn't like the idea of the over-sensualized robot putting IDEAS into his little brother's head.

Even today, Sans sat quietly in his little corner table, watching Papyrus hold Mettaton's hands in his own, leaning down to sweetly nuzzle at Mettaton's face. Sans grimaced, resisting the urge to make a gagging motion. He always behaved himself around his brother, knowing that Papyrus was living a dream come true being in a relationship with his idol, but that didn't mean he could display his displeasure in private.

Instead, he kept back in the corner, extending his magic to listen in.

"...so I have to run back to work," Papyrus was saying. "There's an issue with the new tablecloth orders...Marco asked for mauve and they sent maroon."

Sans rolled his eyes. Papyrus found a job at a posh restaurant and used his overabundance of energy to work both the kitchens and serving, sometimes both in the same day. Sans was a little iffy about the owner Marco; when Papyrus said 'issue', it usually meant 'about three people are losing their jobs as we speak and I have to cover two more shifts to make up for it'.

Mettaton huffed, giving Papyrus a playful pout. "Oh, very well," he said, smiling. "I can wait for Alphys myself. You go and earn that promotion, you." He leaned up and kissed Papyrus on the cheekbone. Sans ignored it for the moment to latch onto that last part. Since when had Papyrus been promoted?

Papyrus beamed. "I'll be over at your place later tonight. I'll even bring those cherries you like for dessert!" He nuzzled Mettaton again before flouncing out the door.

Sans rolled his eyelights, intending to head back to work, but then something caught his attention. As soon as Papyrus was out the door, Mettaton's expression dropped in .2 seconds flat, looking weary and heavy as he sat down at a table and took out his cellphone.

"...Yes, hello, Alphys," he said, his voice having none of his normal perk and charm. "I'm at Grillby's already...what? No, I..." He sighed, rubbing his face with his free hand. "...I don't know if I can keep this up anymore, Alphys...I mean..." Another exasperated sigh. "...he's just too much, you know? I don't know if I can keep doing this! Papyrus...he's such a great guy, but..." He paused, listening in. "...I know, I should just tell him..." He paused again. "...you're right. Of course you're right. I'll see you in a little while then. Goodbye."

Sans felt the telltale flickering of magic in his left eye that A Bad Time was imminent, but he quelled the urge to ruin Grillby's dining area with a Gaster Blaster just for ONE BROTHER-HEART-BREAKING ROBOT.

He KNEW it. He freaking KNEW it! Mettaton was just playing his brother like a violin! Oh no, no no no, that shit was NOT flying!

Sans forced his magic down to avoid breaking anything—his table was already shaking slightly—and slowly stood up, walking over to Mettaton's table and sitting down on the opposite end, startling the robot into looking up.

"Oh! Hello, Sans," Mettaton said, a faint flush on his cheeks. Although there was a truce between them to remain on amiable terms for Papyrus's sake, Sans still made the sins crawl on Mettaton's back whenever they were alone in a room together. And right now, it was less of a 'crawl' and more of an 'angry tap dance'. "...what...can I do for you?"

"Oh, nothing..." Sans said, folding his hands on the table. "Just sittin' for a chat. So, how're things with you an' Paps?" His fingers tensed against the table when Mettaton's expression lightened almost happily, the liar.

"Things are going great!" Mettaton replied, beaming. "Oh, perhaps our work schedules clash sometimes, but other than that we make it work just fine!" His smile wavered slightly at the blank look Sans was giving him. "...Sans, we've had this conversation several times before...and my responses remain the same. So why don't we skip through the Terms and Conditions and just get to why you REALLY sat down?"

Sans scoffed, leaning back. "Fine then," he said, drumming his fingertips on the tabletop. "Toriel said it would be unreasonable to give you the same speech I gave to Frisk's first boyfriend, but what the hell." He stared right at Mettaton, the lights of his eyes gone, leaving just voidlike black sockets.

**"H u r t  m y  b r o t h e r  a n d  y o u ' r e  g o n n a  h a v e  a  b a d  t i m e."  
**

Mettaton blinked, his face twitching slightly. "...a...bit late in the relationship for that talk, isn't it?" he said, letting out a soft breath of nervous laughter. Sans's smile remained frozen and almost murderous. Mettaton sighed, massaging where his temples would be. "Sans, what is this really about?"

Sans's hands flexed together, his left eye flickering blue. "It's about Papyrus's feelings and how I intend that they never be hurt," he replied. "Despite your best...intentions." That last word was almost hissed out.

Mettaton sat back, his expression affronted. "...really, Sans? This pettiness again?" He crossed his arms, scowling. "First of all, despite YOUR best intentions, what goes on between me and Papyrus is NONE of your business, unless either of us WANTS it to be your business, WHICH WE DON'T. Secondly, I would THINK you knew me well enough to know that I would never intentionally hurt him!"

His eyes flicked up to the window, seeing Alphys over Sans's shoulder. "I have to go now," he said, standing up. "And I certainly hope that your attitude is adjusted next time we see each other. I would hate to have to ask Papyrus to give you an adjustment FOR you." He tossed his head, stalking out, taking Alphys with him by the arm.

Sans glowered after him, his eye glowing brightly. "Grillby, I'm takin' a longer break," he announced, standing up. Grillby gave him a 'go ahead' gesture, just looking relieved that Sans didn't Gaster-Blast his restaurant.

* * *

 

Sans was somewhat grateful he didn't see Mettaton for the rest of the week, but he was a little less happy that he'd seen less of Papyrus than normal. It turned out the promotion that was spoken of earlier was Papyrus being promoted to assistant manager and put in charge of scheduling and orders, as well as still doing kitchen and waiting work.

Sans would have thought that Marco was taking advantage of his brother, had Papyrus not insisted he WANTED to still do the kitchen work and waiting tables. The amount of time he was working was the same, but it was Papyrus's discretion of what he did with it by that point, and Marco WASN'T complaining.

Still, what time Papyrus wasn't at work, he was out with Mettaton. And like a creep, Sans was just WAITING for the first sign unhappiness to use as a reason to tear the robot nut from bolt until nothing but a soul remained. Maybe he'd keep it in a jar and shake it every time he felt the urge to.

But every time Sans saw Papyrus, his little brother looked just as happy and perky as ever, and Sans knew Papyrus was the worst liar in the world, so it wasn't FAKED happiness.

He began to think that maybe he had overreacted to the situation and that everything was fine...and then he spotted Alphys standing by his door with a package she meant to deliver to Papyrus from Undyne, talking on the phone while she waited for Sans or Papyrus to come home.

Sans was about to make himself known when he heard her speak.

"Oh, Mettaton, you REALLY shouldn't have waited this long to say something to him!" She sighed, rubbing her forehead. "Look, Mettaton...putting this off isn't helping anything. You're not doing yourself or Papyrus any favors...if you'd just EXPLAIN..." She trailed off. "...yes, I think that would be best. Papyrus is a big boy, he'll understand, I'm SURE of it. Okay, I'll see you later, bye!" She pressed the End Call button and turned around—with Sans not six inches from her.

"Hey, Alphys," Sans said, more than aware that his left eye was glowing. "What's goin' on?"

To her credit, she didn't break down and spill her guts as she normally would have. She DID, however, shove the package into Sans's chest with a loud 'HEREYOUGOTHISISFORPAPYRUSIHAVETOLEAVEBYE!' and bolted off faster than Sans had ever seen her go.

Okay. He was now 93% sure some shady shit was going down behind his brother's back, and was 110% NOT OKAY WITH IT.

 

**(The package for Papyrus turned out to be a custom-made Bone Gundum. Curse Alphys for introducing Papyrus to giant robot anime. Because THAT'S what he needed. An obsession with MORE robots.)**

* * *

 

 

It was now painfully obvious that most everyone else knew something that Papyrus didn't, and they were hiding it from him. They were DEFINITELY hiding it from Sans, which Sans knew would be their undoing. ANYONE involved in hurting his little brother was going to have A Bad Time, and he wasn't afraid to pull out a Gaster Blaster to make it so.

The next time he saw Papyrus and Mettaton together was actually on Frisk's birthday. The kid always spent it at Grillby's, and the proprietor was always more than happy to accommodate for his second-favorite customer.

Everyone arrived right on time, dropped gifts off on the table, and greeted Frisk with congratulations and well-wishing. Mettaton and Papyrus arrived last, fawned over Frisk, and then separated to chat with friends and get refreshments.

Papyrus still looked as happy as ever, so Sans could only speculate that whatever Mettaton intended hadn't been discussed and his brother was still oblivious. That wasn't comforting in the least.

Mettaton stood next to the gift table, setting a couple of things down and jumping when Sans appeared next to him. "Oh—! Sans, you scared me." He gave the small skeleton a smile, but it waned when he saw it wasn't returned. "...Sans, are you still on this belated protective streak?"

"Belated? No. I'm ALWAYS protective of my brother, Mettaton." His left eye flared blue. "Especially when his boyfriend is keeping things from him."

Mettaton's mouth dropped open indignantly, his expression going from insulted to realization to D E T E R M I N A T I O N. He straightened his back, giving Sans an unreadable expression before walking across the room to Papyrus, pulling him off to the side.

Sans frowned, watching intently as Mettaton spoke to Papyrus. Papyrus's expression looked confused, then—to Sans's amazement—apologetic. Papyrus hugged Mettaton tightly and expressed some form of encouragement before nuzzling his face and heading over to get some of Toriel's pie.

More than confused by this point, Sans walked over to the table Papyrus was sitting at and took the seat across from him. "Hey bro," he said, frighting to keep the exasperated query out of his voice. Papyrus gave him a smile.

"Hello, Sans!" he replied, taking a bite of the pie. "Enjoying the party so far?"

Sans drummed his fingers on the table. "Immensely," he said, fighting the urge to start questioning, and losing. "...are...things alright with you and Mettaton? I noticed he looked...worried about something."

Papyrus paused, lowering his fork. "...you heard about that too, huh?" he replied, then sighed. "A bit embarrassing it too so long for him to say something, but I'm not bothered about cutting back on our sex life."

Sans swore he heard something shatter in his mind. "...wut."

Papyrus shrugged, taking another bite of pie. "Mettaton said he's a little overwhelmed by our sex life, and wants to cool it down a little. I'm fine with that, you know?" He paused. "...Er...Sans...are you alright? Sans? Sans?"

* * *

 

"C'mon, kiddo! Please, I swear I'll never ask you for anything else again!"

"Sans, I'm not resetting. Papyrus has a sex life, get over it! Just enjoy the rest of my party!"

"I NEED TO UNHEAR THIS!"

"Oh my god..."

**Author's Note:**

> Ties in with a headcanon that Papyrus is unapologetically blase about sex, and that it's romance he goes gaga about.


End file.
